فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri - Paris Observatory

The interval between two successive passages of the Sun, in its apparent
→ annual motion around the
→ celestial sphere, through a particular point relative to
stars. It is equal to 365.256356 days for the J2000.0 epoch
and is 20m 24.5s longer than the → tropical year.